Synthetic thermoplastic yarn finish



United States Patent Oflice 3,402,127 Patented Sept. 17, 1968 ABSTRACTOF THE DISCLOSURE A synthetic thermoplastic yarn finish having excellentantistatic properties, lubricity and stability in aqueous emulsion isprovided by a mixture of an imidazolinium alkylsulfate, an alkyl esterof a fatty acid, and a water-oil emulsifier for the alkyl ester.

This invention relates to a finish for synthetic thermoplastic yarn.

Some synthetic thermoplastic yarns are made of nylon, nylon copolymers,polyesters, polyester copolymers, and the like.

Nylon is a long-chain synthetic polymeric amide having recurring amidegroups as an integral part of the main polymer chain, and is capable ofbeing formed into a filament in which the structural elements areoriented in the direction of the axis. Nylon includes nylon-66(polymeric hexamethylene diammoniumadipate), nylon-6 (polymeric6-aminocaproic acid), nylon-610 '(polyhexamethylene sebacamide),nylon-4, nylon-7, nylon-11, etc., and fiberforming co-polymers thereof.

Polyester is a long-chain synthetic polymer composed of at least 85percent by weight of an ester of a dihydric alcohol and terephthalicacid.

In manufacturing textiles from synthetic thermoplastic yarn, variousoperations are preformed that require coating the yarn with finisheswhich provide lubricity, antistatic and other properties necessary forsatisfactory processing and handling. Depending upon the end use,different finishes may be required for the same kind of yarn.

In a particular instance, when nylon yarn to which a standard finish hadbeen applied was used as filling yarn in the quill of a weaving loom, itwas determined that lubrication was excellent and quill take-offtensions were low and uniform. Nevertheless, the yarn had poor cohesiveand antistatic properties which made it difiicult to handle duringweaving. In a second instance, another standard finish was placed onnylon yarn with the result that the cohesive and antistatic propertieswere excellent; yet, this yarn exhibited high friction characteristics.Poor lubricity resulted in high, erratic quill take-E tensions thuscausing streaky fabric and very distinct quill junctions. Other finishesthat were tested also produced yarn having various desirable weaving anddyeing characteristics.

Therefore, it is an object of this invention to provide a finish forapplication to synthetic thermoplastic yarn wherein the yarn will haveexcellent lubricity, bundle cohesion and antistatic properties providingexcellent weaving characteristics for filling yarns.

Another object is to provide a finish for synthetic thermoplastic yarnthat will improve the dyeability of fabrics produced therefrom.

Other objects will become apparent from the following descriptivematerial.

The above objects are achieved in the provision of a finish forsynthetic thermoplastic yarn comprising a lubricant, an emulsifyingagent and an antistatic agent. Based on its weight, 40-70 percent of thefinish is lubricant, 20-60 percent is an emulsifier or a mixture ofemulsifiers, and 5-20 percent is a quaternary imidazolinium compoundhaving the general formula:

N-CH:

wherein R is an aliphatic radical having from 10 to 20 carbon atoms andcontaining at most three carbon to carbon double bands, R is a saturatedaliphatic radical having from 2 to 6 carbon atoms, and R is a C H OHradical with n being an integer from 1 to 5.

A quite suitable lubricant for use in the instant finish is a member ofthe class of fatty acid esters represented by the general formula RCOORwherein R is a saturated aliphatic radical containing 1-22 carbon atomsand R is a saturated aliphatic radical containing 1-12 carbon atoms.Examples of these esters are butyl stearate, butyl laurate, butylmyristate, butyl palmitate, isopropyl palmitate and neopentyl stearate.

Usually the subject finish is applied to yarn as an aqueous emulsion.Therefore, it is necessary to' provide a water-oil emulsifier for thelubricant in the finish. There are many water-oil emulsifierscommercially avilable, for example, Aerosol AY (diamyl sulfosuccinate),Dispersant NI-O (ethylene oxide condensation product with alkyl phenol),Ninox BDO (ethylene oxide condensation product with alkyl phenol), andSynthetics AD 50 (polyethylene glycol ether of hydroabietyl alcohol).Two products sold by Atlas Powder Company of Wilmington, Del., have beenfound to be particularly effective. These products are sold under thetrademark Span and Tween. Span is a random mixture of partial esters offatty acids and hexitol anhydrides (hexitans and hexides) derived fromsorbitol. The structure of Span compounds is shown below:

CH CH-CHzOOCR HO-CH CH-OH no-onAor-r,

(311% CH-OOCR wherein R is a saturated aliphatic radical containing from5 to 20 carbon atoms. Examples of compounds covered by the trademarkSpan are random mixtures of a plurality of forms of either sorbitanmonolaurate, sorbitan monopalmitate, sorbitan monostearate, or sorbitanmonooleate.

The emulsifier Tween, composed of a random mixture of components, canbeobtained by adding'bxy ethylene chains to the non-esterified hydroxylsof a Span mixture. Tween has the composition shown by the structuralformulas 'below:

CH: CI-I-CHzOOCR wherein R is a saturated aliphatic radical containingfrom -20 carbon atoms and n +n +n =1l0O ethylene oxide groups. Propyleneoxide units can also be used rather than ethylene oxide to produce alike material, however, ethylene oxide is preferred.

Both of the above described emulsifiers (Span and Tween) are randommixtures. As used herein, random mixture means a combination ofcomponents whose relative proportions are not critical. That is, theindividual components can be present in the combination in any and allproportions with respect to each of the other components withoutchanging the end result, i.e., proper emulsification, obtained by thecombination of components. In the instant finish it is possible to useeach of the emulsifiers Span and Tween alone or in combination with oneanother. A combination is preferred, for Span is lipophilic or oilloving and Tween is hydrophilic or water loving thereby producing abetter emulsion than would one emulsifier alone.

It must be understood that any kind of emulsifier capable of performingthe same function, i.e., suitably emulsifying the lubricant with water,is quite as suitable as either Span or Tween or a combination thereoffor use in the subject finish.

As synthetic thermoplastic yarns are processed they becomeelectrostatieally charged. These charges, generated both by rubbing ofyarn or fabric with one another and by rubbing against other bodies,give rise to various disadvantages than can show themselves in manyways, depending upon the yarn and the use thereof. Electrostaticallycharged yarns and fabrics may not only repel one another but may alsoattract and hold dirt, dust, lint, and the like. Weaving and otherfabric manufacturing operations are made more difficult by electrostaticcharges on the yarn which cause flaring filaments. In order to overcomethese difficulties, it is necessary to use an antistatic agent in thefinish. Generally, antistatic agents contain ionizable and/orhydrophilic groups which enable them to dissipate static charges. Theseagents are generally long-chain, surface active, non-ionic or cationicsurfactants, although anionic materials have been found to be somewhateffective. Cationics generally used as antistatic agents includequaternary ammonium halides, alkyl imidazoline hydroactetates, alkylbetaines, and fatty acid polyamine condensates. Cationic antistaticagents have longer lasting effectiveness than do non-ionic agentsbecause they are more difficult to remove during laundering and drycleaning.

As noted hereinabove, cationic antistatic agents possess certaindesirable properties, but it was expected that a cationic antistaticagent would precipitate when used in conjunction with the hereinabovedescribed lubricants (fatty acid esters) and emulsifying agents (Spanand Tween). Nevertheless, when an attempt was made to use a quaternaryimidazolinium'compound' (a cationic antistatic agent), having astructure such as that shown hereinbefore, in conjunction with a fattyacid ester and emulsifiers Span and Tween, surprisingly, noprecipitation occurred and an excellent, quite stable emulsion wasobtained when this finish was homogenized with water.

Among the quaternary imidazolinium compounds suitable for use in thepresent finish are l-(2-hydroxyethyl)- l-ethyl-2-oleyl-imidazoliniumethyl sulfate, 1-(2-hydroxyethyl)-l;ethyl 2 stearyl-imidazolinium ethylsulfate, 1-(2- hydroxyethyl) -l-ethyl-2-linoleylimidazolinium ethyl'sulfate, 1. (4-hydroxybutyl)-1-ethyl-2-oleylimidazolinium ethylsulfate, 1 (5 -,hydroxypentyl)-l-propyl-2-stearylimidazolinium propylsulfate, 1 (5 hydroxypentyl)-lethyl-Z-oleyl-imidazolinium ethyl sulfate,l-(hydroxymethyl) l ethyl-2-pentyl-imidazolinium ethyl sulfate,l-(4-hydroxybutyl) -1-butyl-2-stearyl-imidazolinium butyl sulfate, 1(5-hydroxypentyl)-l-propyl-2-oleyl-imidazolinium propyl sulfate,l-(hydroxymethyl)-l-hexyl-2-oleylimidazolinium hexyl sulfate.

An aqueous finish composition is prepared by homogenizing finish,composed of lubricant, emulsifying agent or mixture of agents, and anantistatic agent (a quaternary imidazolinium compound), with water. Thegenerally desirable ranges for each of the finish components, expressedin weight percent based on total finish weight, are shown in the tablenext below.

TABLE I.GENERAL FINISH COMPOSITION Component: Range, weight percentLubricant 40-70 Emulsifying agent 20-60 Antistatic agent (quaternaryimidazolinium compound) 5-20 Usually, as noted before, the emulsifyingagent is composed of two components: 1) material designated by thetrademark Span and (2) material designated by the trademark Tween. Thesetwo materials can be present in the finish in various proportions.However, a desirable percent range for each material based on totalemulsifier weight is set forth in the table next below.

TABLE II.EMULSIFIER COMPOSITION Component: Range, weight percent Span t60-80 Tween 20-40 Usually the instant finish is present on yarn treatedtherewith in an amount from about 0.5 to 1.2 percent based on yarnweight.

There are various methods for applying the subject finish to yarn. Inone method the yarn passes in contact with a roller or wick partiallyimmersed in aqueous finish composition. Other finish application methodsconsist of spraying, brushing, or immersing the yarn in an aqueousfinish composition bath.

The amount of finish and water in the aqueous finish composition mayvary. Concentration can depend, among other things, upon the particularimpregnation method employed and on the kind of filaments treated.Aqueous finish compositions having from about 3 to about 48 percentfinish therein based on the total weight in the aqueous finishcomposition are quite suitable.

The examples set out hereinafter are intended to illustrate theinvention. They are not intended to limit the invention in any mannerwhatsoever.

Example I A particular finish was prepared in the following manner. Amixture of materials shown in the following table in the indicatedproportions based on the total weight of all components was prepared.

TABLE III.FINISH COMPOSITION Component: Percent by weight Butyl stearate60 Mixture or sorbitan monolaurates (Span 20 Mixture of polyoxyethylenesorbitan monolaurates (Tween 20) (2O ethylene oxide units) 101-(2-hydroxyethyl) -1-ethyl-2-oleyl-imidazolinium ethyl sulfate 10 Whilebeing mixed, the finish was heated to 50 C. and then added to waterwhich also had been heated to 50 C. The final aqueous finish compositionwas 16 percent finish and 84 percent water based on the total weight ofthe aqueous finish composition. Then the mixture was fed through ahomogenizer thereby forming a stable emulsion of finish in water. Afterhomogenizing the aqueous finish composition was cooled to C.

This aqueous finish composition was then applied to a bundle of meltspun34 nylon-66 filaments having a total denier of 185, at a point betweenthe spinneret and the bobbin used to take up the filaments. The yarn wasthus coated with 1 percent finish based on yarn weight. These filamentswere then drawn on a conventional draw-winding machine employing twosets of rolls; a draw-pin between said rolls, around which the yarn wassnubbed; and a take-up assembly in which the yarn was collected on abobbin. Between the two sets of rolls, the filaments were drawn 2.63times.

The emulsion appeared to be quite stable, showing no signs of separationinto an oil and aqueous phase at any time during its use.

The yarn with the instant finish applied thereto was shipped to aweaving mill. There it was used as filling yarn in the weaving process.Filling yarn is wound on a small spool or quill which is placed on theshuttle of a loom.

Fabric woven from the above described yarn proved to be extremelypleasing in appearance with significant reduction in dye streaks, bands,and quill junctions. The yarn exhibited very good lubricity, excellentbundle cohesion and good antistatic properties during the weavingoperation.

Example II A yarn made from nylon-66 consisting of a bundle of 34filaments having a total denier of 70 was treated with the finishdescribed in Example I. It was compared with a competitive yarn havingthe same denier and number of filaments. Fabric samples were then wovenusing in one sample, yarn treated with the finish of the invention and,in a second sample the competitive yarn, as fill yarn. Fabric havingfill yarn treated with the inventive finish had fewer streaks, bands,and quill junctions than did fabric wherein the fill yarn was acomparable, competitive yarn treated with another kind of finish.

The improved lubricity provided by the subject finish is indicated bythe fact that the competitive yarn showed 1820 grams tension on the yarnduring quilling while yarn treated with the inventive finish measuredonly 14-16 grams tension under identical quilling conditions.

Yarn treated with the inventive finish shows marked advantages.Lubricity is significantly increased, generation of static electricityis depressed, and bundle cohesion is notably increased.

The invention has been described by referring to specific embodiments,but it should be understood that nu merous modifications can be madewithout departing from the scope and spirit of the invention which isonly limited by the appended claims.

What is claimed is:

1. A finish consisting essentially of to 70 weight percent of a fattyacid ester having the formula RCOOR wherein R is an alkyl radicalcontaining 1 to 22 carbon atoms and R is an alkyl radical containing 1to 12 carbon atoms; 5 to 20 weight percent of a quaternary imidazoliniumcompound having the formula N-CH 2 Ri-G RzOSOg" N-CHz R2 R3 wherein R isselected from the group consisting of oleyl, linoleyl and an alkylradical containing 10 to 20 carbon atoms, R is an alkyl radicalcontaining 2 to 6- carbon atoms and R is a C H OH radical with n beingan integer from 1 to 5; and 20 to 60 weight percent of at least oneemulsifier selected from the group consisting of compounds having theformulae CH CH-CHzOOCR CH-OH I OH ITO-CH 10H;

CH2 CIT-O O O R CH2 CHCH2OOCR References Cited UNITED STATES PATENTS3,125,487 3/1964 Hutchinson 117139.5 3,277,079 10/1966 Press 117--139.5

OTHER REFERENCES Technical Bulletin, Atlas Spans and Tweens, AtlasPowder Co., 1945, pp. 1, 2, and 12.

The Condensed Chemical Dictionary, 6th edition, Reinhold, 1956, p. 189.

LEON D. ROSDOL, Primary Examiner.

STANLEY D. SCHWARTZ, Assistant Examiner.

